Cam

ABSTRACT

A facsimile transceiver unit utilizing a drum wherein the drum gripper bar must be at a predetermined location when the drum is brought to a stop. Control circuitry stops the drum with the gripper bar within a certain window. An improved cam surface raises the gripper bar while at the same time rotating the drum so that the gripper bar is moved to a predetermined location within the window.

United States Patent [191 11] 3,854,715 Coleman Dec. 17 1974 [54] CAM 2,666,808 l/l954 Cooley 346/l38 X 1 l B dd d 3' [75] Inventor: John F. Coleman, Rochester, NY. 3618l23 1/1971 u en eck 46/138 [73] Assignee: Xerox Corporation, Stamford, P i Examiner Ev r C, Blunk Conn- Assistant ExaminerBruce H. Stoner, Jr. [22] Filed:- Mar. 19, 1973 21 Appl. No.: 342,640 5 3 ABSTRACT A vfacsimile transceiver unit utilizing a drum wherein the drum gripper bar must be at a predetermined loca- L 1 ifi tion when the drum is brought to a stop. Control cir- [58] Field of Search 271/53, 82;,346/138, 125, mp3 drum with gripper bar a [56] References Cited UNITED STATES PATENTS 2,622,517 12/1952 Denison et 346/138 X certain window. An improved cam surface raises the gripper bar while at the same time rotating the drum so that the gripper bar is moved to a predetermined location within the window.

2 Claims, 4 Drawing Figures morev particularly;- to. :an zimproved.cam contiguration for impartingtwo directionsv ofirnovementto a cooperating-member.

In; alfacsimiler'transceiver -unit. utilizing :a drum for conveying-sheet materiallpasua.scanning station, a gripper bar. .which rotatesvwithxthexdrum is conventionally V used forL-holdinguathesheet materialtotheadrum. This gripper baris "normally biasedt toward the 'drum andis raised away from-the jdrum by ;a camsurface when it is desired: to either remove: a sheet from theidrum' or place a;sheet incontact withttheadrum. Suchiane arrangement isidisclosed;for-.exampIe,:ini.U;Si Pat.fN0."3,6l8,123.111 1 a facsimile transceiver unit wherein documents-are automatically fed-ontoandaoff thetdrum, tsuch ias' that disclosed in.copending application:SerZ'No.. .253 ,72'1 filed Mayv l 6, 1972, and; assigned to theassigneeoftheapresent;-invention:now-U;S1' 'Iat. No. 3 {790,1 59,! it is necessary.tostop the drumsataapredeterminedlangular position ,so (that theagripper banisiinthe propenplace to receive sheets; lllustrativecontrol:apparatusfor performingagthis :positioning function.;is..disclosed Jin v:copendin'g .abandoned,,andassignedgtoa the assignee-of the-present invention.v The apparatus :disclosedF in the last- I s a s-4,715

2 H tatingon shaft 10. Gripper bar is utilized'to hold ,sheet material" against drum l7'and is described in detail intheaforementioned US. Pat. No.3,6l8,'123. Spring'23biases gripper bar20 against the surface of drum 17. Lever arm is pivotably supported on shaft 27-and includes cam surface 28at one end thereof. At the other end of lever arm- 25 is surface 29. When surface '29 ismoved down, surface 28 engages the lower 7 end of gripper bar 20, thereby raising gripper bar'20 this-angular position.

away from drum surface 17. Cam surface 28 is arranged to have a radial inclination so that when raised,

drum 17 'may be rotated ina clockwise direction and gripper bar 20 will ride up on cam surface 28. However, whendrum 17 is at rest'and cam surface 28 is raised, it will only raise gripper bar 20 invthe angular position at whichit is at rest, making no adjustment of Turning now to'FIG. 2, depicted therein is the apparatusof FIG. 1 wherein an improved cam surface 30 embodying the principles of this invention is employed. When'the illustrated apparatus is utilized in an automatic facsimile transceiver such as that disclosed in the aforementioned US. Pat. No. 3,790,159, it is necessary forming this functionmay illustratively be of the type disclosedin the aforementioned copending application Ser. No. 253,726. This illustrative control apparatus 50 stops the drum within an angular window of approxitmentioned,.copendinggapplicatim .will:stop.the :drumso "mately 8 before the topmost position. In order to bring asrto positionctheggripperJbar @within"a-icertain ian'gular window. lrlowevergfor"maximumrsheet ifeedingqeliability .itisvdesirable;tothave.atherdrumsstopped so'rthat iithe gripperban is ataa :particular i-location within "thatwindow,

SUMMARY -OF"THEEINVENTIGN In accordance With'ith principles *ofz this invention,

Y an improved cam surface configuration aislprovided for gripper bar20closer to the topmost position, cam surfore, when lever arm 25 is pivoted, the inclination of surface 32 will force gripper bar 20 so that its bottom end will be moved into the notch to point 33, thereby both raising the-tgripper bmiandlmovingthesdrum so 40 rotating drum '17 and'consequently gripper bar 20 to that thegfriplpertbar isvbrought to .a predetermined location within the angularawindow-inrwhich'the gripper bar is initially stopped. The cam surface 1 comprises two rampsforminganotchxtherebetween. When the cam surface is raised against "the lower send-of the gripper bar, this lower endzlis.forced:into-:.thenotch; thereby moving-the gripper bar to the predetermined location as it is raised.

DESCRIPTION OF'THE DRAWING The foregoing .willkbecomemore readily apparent upon reading -.;the following description in conjunction with the drawing in which FIG. ldepicts illustrative priorart-apparatus utilizing a cam to raisea gripper-bar,

FIG. 2 depicts illustrative apparatus-employing a cam embodying the principles of this invention wherein the cam is in an unengaged position, I

FIG. 3 depicts the-apparatus ofFIG 2 wherein the camis in an engaged position, and

FIG. 4 is a perspective -vie.w of' the illustrative cam shown in FIGS. .2and: 3.1. g

DESGRIPTION' 0F THELIILLUSTRATIVE' EMBODIMENT-"1 Referring-t0 FlG-- 1', depictedtherein is a portion of a prior art facsimile transceiver includingdrum l7 rothe topmost position of the 8 angular window, as shown in FIG. 3. Y

FIG/4 is a perspective view'of lever arm 25 having improved cam surface 30 thereon.

Accordingly, there has been shown an improved cam surface for imparting both radial and angular motion to v a rotatable drum for conveying sheet material,

a gripper bar extending through the surface of said I drum and rotating with said drum, said gripper bar being biased toward the center of said drum for engaging an edge of saidzsheet material in fixed relationship to said drum surface, and means for simultaneously moving said gripper bar radially outward from said drum and rotating said drum to a predetermined angular position including acam movable from a first to a secondposition, said cam having a notched surface for engagement with said gripper bar as said cam is moved from 2. The combination of claim 1 wherein said cam sursaid first position to said second position, said first position being closer to the center of said drum and farther from the surface of said drum than said sec- Spec to one another so as to form mtch' nd position. 5

face includes a pair of ramp surfaces inclined with re- 

1. In facsimile apparatus, the combination comprising a rotatable drum for conveying sheet material, a gripper bar extending through the surface of said drum and rotating with said drum, said gripper bar being biased toward the center of said drum for engaging an edge of said sheet material in fixed relationship to said drum surface, and means for simultaneously moving said gripper bar radially outward from said drum and rotating said drum to a predetermined angular position including a cam movable from a first to a second position, said cam having a notched surface for engagement with said gripper bar as said cam is moved from said first position to said second position, said first position being closer to the center of said drum and farther from the surface of said drum than said second position.
 2. The combination of claim 1 wherein said cam surface includes a pair of ramp surfaces inclined with respect to one another so as to form a notch. 